Blowpipe nozzle



K. SUD HAUS BLOWPIPE NQZZLE Filed Sept. 3, 1931 Sept. 14, 1937.

2 Sheets-Sheet l v T e K. sum-mus BLOWPIPE NOZZLE Filed Sept. 5, 1931 Sept. 14, 1937.

2 Shets-Sheet 2 Patented Sept. 14, 1937 BLOWPIPE NOZZLE Karl Sudhaus, Remscheid, Germany, assignor, by mesne assignments, to Union Carbide and garllzon Corporation, a corporation of New Application September 3, 1931, Serial No. 560,995 In Germany September 12, 1930 18 Claims. (Cl. 158-27A) This invention relates to blowpipe nozzles, and

more particularly to nozzles adapted to utilize a mixture of a combustible gas and a combustionsupporting gas in order to heat portions of a metallic surface to be hardened.

To obtain a uniform condition of surface hardness it is necessary that the article to be hardened not only be heated to a temperature within a certain definite range to avoid an overheating of the article on the one hand and to obtain an adequate heating to a temperature above the hardening temperature on the other hand, but also each portion of the surface must be heated at the same rate. Slight differences in the rate of 5 heating of adjacent portions treated simultaneously produce considerable differences in the hardness of such portions, resulting in uneven wear of the hardened surface. To obtain a completely uniform hardness of large surfaces, the effective core or inner zone of the heating flame employed should burn evenly and have no irregularities whatever throughout the whole length of the flame.

Heretofore nozzles or burner tips used for the production of wide heating flames have either consisted of welding and soldering burners converted to a use to which they were only slightly applicable, or special nozzles having a plurality of tips arranged side by side. Neither of these 30 types produce wide flames of the same intensity Fig. 2 is a vertical longitudinal section of the same, taken along line II-I I of Fig. 1;

Figs. 3 and 4 are vertical cross-sections taken 45 along the lines IIIIII and IVIV, .respectively,

of Fig. 1; I

Fig.5 is a horizontal longitudinal axial section of another burner tip embodyingthis invention; Fig. 6 is a vertical longitudinal section of the burner tip of Fig. 5, taken along the line VI-VI; and

Fig. 7 is a vertical cross-section of the burner 'tip of Fig. 5, taken along the line VII-VII. 55 In general terms, an improved burner tip embodying this invention has an entrance passage leading to a chamber having walls, a portion of which diverge toward the orifice along one longitudinal section and converge toward the orifice along a longitudinal section perpendicular to the first. In addition, the cross-sectional area of the chamber or channel, by the proportionment of the divergence of the lateral walls to the con vergence of the upper and lower walls, may first increase and then decrease, or may continually 10 decrease.

Figs. 1 to 4 illustrate a burner tip a constructedin accordance with this invention, which is provided with an inlet b, adapted to be connected to the mixing chamber of a blowpipe which will deliver a mixture of combustible and combustion-supporting gas, such as oxygen and acctylene, to the burner tip. Leading from the inlet is a channel or chamber g which may terminate in a discharge slot 0. The lateral walls (Fig. 1) 30 of the chamber g are divergent from the inlet to a point at a distance m from the discharge end of the burner tip, at which point these walls become parallel and continue so to the discharge slot. The upper and lower walls (Fig. 2) of the chamber 9 may be convergent from the inlet b to the discharge slot c. The length l of the .discharge slot is preferably approximately equal to the width of the surface which is to be heated, and the width 11 of the slot is extremely small, being in one instance 0.8 mm. (0.0118 in.)

The area of the slot is preferably less than the cross-sectional area of the inlet b. As mentioned before, by properly proportioning the di- I vergence of the lateral walls and convergence of the upper and lower walls, the cross-sectional 'area of the passage 9 may gradually increase from the inlet b to a maximum at a point between the inlet and the discharge slot and then gradually decrease to the area of the slot. The maxi- 40 mum cross-sectional area may occurat the point, the distance 114 from the discharge orifice, at which the lateral walls become parallel, or it may occur between the inlet b and that point. However, the convergence and divergence of the walls may be so proportioned that the cross-sectional area will decrease throughout the whole length of the burner. The parallel portions of the lateral walls will 5 direct the stream in a straight jet with an equalized velocity front, so that the gas' will issue at a constant rate from each portion of the orifice the discharge end of the burner tip may be thickened and provided with a system of water passages i in order to provide adequate cooling of the burner.

In the second embodiment shown in Figs. 5 to '7, the burner tip a is provided with an inlet 12 as in the first embodiment, and a chamber 9 having successively divergent and parallel lateral walls and successively convergent and parallel upper and lower walls. The converging upper and lower walls, however, become parallel at a distance 11.: from the discharge slot 0, which is equal to or less than the distance 111 over which the lateral walls are parallel, thus forming a discharge portion 0 having parallel upper and lower and parallel lateral walls for the distance 11:. The cross-sectional area varies in the same manner as that of the burner tips of Figs. 1 to 4, with the exception that since there is provided a .discharge portion of constant cross-sectional area, that part of the chamber g having parallel lateral walls and converging upper and lower walls may be shorter or entirely omitted. With such a portion of constant cross-sectional area the equalization of the velocity front is completely assured. With such a portion and the increasing and decreasing phase or the chamber 9, there will be three portions of the burner; a first of increasing, a second of decreasing, and a third of constant cross-sectional area. As before, the thickness d of the slot is very small, and the width 1 is preferably approximately the width of the surface to be treated. For cooling purposes, the upper and lower walls or the whole tip may be thickened and the water passages omitted.

The upper and lower walls of the burner illustrated in Figs. 1 to 4 may become parallel at a distance n: from. the discharge slot 0, and form a portion 0 having a constant cross-sectional area, as in the second embodiment. In addition the length of the parallel portion of the upper and lower walls may be made equal to the length of the parallel portion of the lateral walls. Other changes may be made without departing from the spirit or this invention, such as passing a single gas, rather than a mixture or gases, through the nozzle.

What is claimed is:

1. A blowpipe nozzle comprising a chamber having an inlet and an outlet, the lateral and upper and lower walls of said chamber forming two adjoining and integrally united portions, the lateral walls or the first portion being divergent and the upper and lower walls thereof being convergent, and the lateral walls of the second portion being parallel and the upper and lower walls thereotbeing separated by an average distance less than the average distance separating the said upper and lower walls throughout the length of said first portion, and said walls terminating at said outlet in an elongated discharge orifice, theparallel lateral 'walls of said second portion being adapted to equalize the rate or fiow of gas so as to produce a jet having a uniform velocity over the width or the discharge orifice.

2. A blowpipe nozzle as defined in claim 1, in which the area of said outlet is less than the area of saidinlet.

3. A blowpipe nozzle comprising a chamber having lateral and upper and lower walls forming two adjoining and integrally united portions, said lateral walls being divergent and said upper and lower walls being convergent throughout the length or said first portion, and said lateral walls being parallel throughout the length of said sectoward the delivery orifice;

0nd portion, the length of said second portion being greater than the distance separating said lateral walls when parallel, and said parallel lateral walls being adapted to equalize the rate of fiow of gas so as to produce a jet having a uniform. velocity front. 4. A blowpipe nozzle as defined in claim 3, in which the average cross-sectional area of said second portion is less than the average cross-sectional area of said first portion.

5. A blowpipe nozzle comprising a chamber having an inlet portion and an outlet portion, and a transversely elongated discharge orifice, said inlet portion having two of its opposite sides diverging and the other two opposite sides converging toward the outlet portion, the outlet portion having two of its opposite sides formed substantially parallel with each other and the other opposite sides formed slightly converging toward each other, in such a manner as to produce a smooth passage for the gas through said outlet portion, said outlet portion terminating in an elongated narrow discharge orifice whose lips are separated by a distance suitable to cause the gas to issue therefrom in the form of an elongated jet having a uniform velocity over the width of the discharge orifice.

6. A longitudinally and transversely elongated blowpipe nozzle having a flat transversely elongated discharge orifice and comprising two adjoining and integrallyunited portions, one of said portions being formed by lateral walls which diverge, and upper and lower walls which converge in the direction of the gas discharge orifice, and the other or said portions being formed by lateral walls which are substantially parallel to each other, and by upper and lower walls which are substantially convergent, the upper and lower walls of both portions having a surface area which is greater than the surface area of said lateral of the second portion being such that at the gas discharge orifice the said walls are separated only by an elongated narrow delivery slot, whereby said blowpipe nozzle is elongated both in the direction or the fiow oi the gas and transversely of said direction of flow, and whereby an elongated narrow jet of gas having an equalized velocity front is caused to issue from said delivery slot.

'7. A blowpipe nozzle having a chamber provided with a gas intake and an elongated and narrow delivery orifice; two walls of said chamber converging gradually from the gas intake to the narrow delivery orifice and forming the lips thereof, and the two other lateral walls diverging gradually'from. a point adjacent the gas intake to a point intermediate the gas intake and the delivery orifice; the simultaneous divergence and convergence 0! the opposite pairs of walls forming a chamber portion having a gradually reduced cross-sectional area from the gas intake said lateral walls extending substantially parallel the point where the divergence terminates to the delivery end of the nozzle and being spaced from each other by the elongated and narrow delivery orifice; the parallel spacing of the lateral walls adjacent the delivery end or the nozzle serving to equalize the rate of flow of gas to produce a Jet having a uniform velocity over the width of the delivery orifice. r

8. A blowpipe nozzle as defined in claim '7, in which the distance the lateral walls extend substantially parallel to each other is longer than walls, and the convergence of the larger walls to each other irom I the transverse length of the elongated and narrow delivery orifice.

9. A blowpipe nozzle as defined in claim 7, in which the longitudinal distance the lateral walls diverge within said chamber is longer than the transverse length of the elongated and narrow delivery orifice. v

10. A blowpipe nozzle having an inlet, a chamber having successive portions, one of increasing and decreasing cross-sectional area, and another of continually decreasing cross-sectional area, terminating 'in a transversely elongated discharge orifice, said increasing and decreasing portion of said chamber having diverging lateral walls and converging upper and lower walls, and said decreasing portion having parallel lateral walls and converging upper and lower walls terminating at said orifice.

11. A blowpipe nozzle as defined in claim 10,

in which the length of the portion of increasing.

and decreasing cross-sectional area is greater than the width of the transversely elongated discharge orifice.

12. A blowpipe nozzle as defined in claim 10, in which the length of the portion of increasing and decreasing cross-sectional area is greater than the length of the portion of decreasing cross-sectional area.

13. A blowpipe nozzle comprising a single cham her having two adjoining portions, the adjoining portions having walls terminating in a transversely elongated delivery orifice at the discharge end of ,the chamber, said first portion being formed in a manner to have cross-sections of successively gradually increasing and decreasing area over the length thereof; and said second portion having parallel lateral walls adapted to produce a jet having an equalized velocity front.

'14. A blowpipe nozzle as defined in claim 13, in which the axial length of the first portion of said chamber is greater than the transverse length of the gas delivery orifice.

15. A blowpipe nozzle provided with a chamher having lateral walls in successive divergent f and parallel relationship, and upper and lower walls in successive convergent and parallel relationship, said chamber terminating in an elongated discharge slot having a width less than the length of the parallel portion of said lateral walls.

16. A blowpipe nozzle having an inlet and walls extending therefrom forming a plurality of integrally united portions and terminating in an elongated discharge orifice, a portion adjacent said inlet having divergent lateral walls and convergent upper and lower walls and a portion adjacent said discharge orifice having parallel lateral walls and parallel upper and lower walls, the parallel lateral walls of said last-mentioned portion being adapted to produce a jet discharging from said orifice having a uniform velocity over the width of said orifice.-

17. A blowpipe nozzle having walls forming a chamber having successive portions of increasing, decreasing and constant cross-sectional area,

said chamber terminating in an elongated discharge orifice having a width of less than about 0.12 in. and having parallel lateral walls adjacent the discharge orifice which are adapted to equalize'the rate of flow of gas so as to produce a jet having a uniform velocity over the transverse length of the delivery orifice.

18. A blowpipe nozzle provided with a chamher having lateral and upper and lower walls forming a plurality of integrally united portions and terminating in an elongated discharge orifice, the first of said portions having divergent lateral walls and convergent upper and lower walls adapted to provide a gradually increasing cross-sectional area, the second portion adjacent said first portion having parallel lateral walls and convergent upper and lower walls adapted to provide a gradually decreasing cross-sectional 7 area, and a portion adjacent said discharge orifice having parallel lateral walls and also parallel upper and lower walls adapted to provide a constant cross-sectional area.

- KARL SUDHAUS. 

